1. Taking the Multibeam Jump
2011 RESON User Conference
Taking the Multibeam Jump
A rough guide based on experiments with RESON multibeam echosounders
Jean-Guy Nistad & Mathieu Rondeau

2. Introduction
Example of survey well suited for small enterprises: bridge pier mapping

3. Introduction
Integrated (IMU + MBES), portable, pole-mounted solutions used on vessels of opportunity
RESON Hydrobat
(source: RESON)
WASSP
(source: ENL Electronic Navigation Ltd.

4. Introduction Problem: multibeam integration is complex
Solution: share lessons from experiences with Seabat 7125 integration
Three requirements are of importance:
Measure all relative locations and sensor orientations
Be aware of the sensor connection layout
Anticipate the data processing workflow

5. Lever arms & orientations
Scenario 1 X
-3.512m
POS/MV 320 X Y
-0.207m Y Z
-2.604m
-1.835m
-1.902m
0.674m
0.665m
Reference Point
SeaBat 7125 X Y
1.648m Z
0.596m

6. Lever arms & orientations
Defining the Ship Reference Frame
X vessel
Z vessel T
Pitch +
Z vessel R
Roll
Y vessel +

7. Lever arms & orientations
Scenario 2 Y X Z
-0.658m
-4.109m
-0.895m
-0.456m
-0.975m
0.275m
-0.817m
Centre of gravity

8. Lever arms & orientations
Measuring the IMU mounting angles
Y vessel Az
Heading
X vessel +
Z vessel T
Pitch
X vessel +
Y vessel
Z vessel R
Roll +

9. Lever arms & orientations
Measuring the sonar mounting angles
Y vessel +
Heading
30° starboard tilt
X vessel Az
Z vessel T
Pitch
X vessel + R
Z vessel
Roll
Y vessel +

10. Lever arms & orientations
Incidence of 90° starboard rotation of the IMU
X vessel +
X IMU
Y IMU Az
Y vessel
Only detected with the 30° sonar tilt!

11. Lever arms & orientations
Roll stabilization issue with 30° sonar tilt
Quay side wall
Seabed ?
Missed side wall
No roll stabilization
Roll stabilization

12. Lever arms & orientations
Scenario 3
Almost same as scenario 2
Simulating an integrated pole-mounted system
For integrated systems, IMU – MBES are factory aligned. How then should they relate to the SRF?

13. Lever arms & orientations
Scenario 3 +
Heading
Y sonar Az
X sonar +
Z sonar
Pitch T
X sonar
Z sonar +
Roll R
Y sonar

14. How does the chosen layout affect timing latency issues?
Connection Layouts
Many different possible inter-sensor connection layouts
How does the chosen layout affect timing latency issues?

15. Connection Layouts
Full serial (RS232, RS422) + Sonar PC + =

16. + = Connection Layouts Serial + USB between sonar and PC
Processing Box

17. + = Connection Layouts Serial + LAN between sonar and PC
Processing Box

18. + = Connection Layouts Serial + LAN between sonar and PC
Processing Box

19. How does one solve for IMU latencies?
Connection Layouts
Latencies will vary depending on chosen layout
The conventional patch-test will solve for GPS – sonar latency but not IMU – sonar latency
1 PPS is mistakenly seen as the ultimate solution to all latency issues
How does one solve for IMU latencies?

20. Timing latencies Source: GeoSwath Plus Operation Manual
Source: Lockhart, Arumugan, Precise Timing and TrueHeave® in Multibeam Acquisition and Processing

21. Data Processing Workflow
PDS2000
Raw bathymetry
More control in post-processing but harder to setup
S7KPDS
RESON Seabat 7125
Corrected bathymetry
Easier to setup but less control in post-processing
QINSy
CARIS
HIPS & SIPS
XTF
RESON Seabat 8101
Hypack
HSX

22. RESON, Applanix, CARIS & QPS
Conclusion
Other helpful tips:
Get familiar with standard hydrographic practices
Get friends in the Support department!
Many thanks to
RESON, Applanix, CARIS & QPS